#include <termios.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <string.h>
 #include <jni.h>
 #include <strings.h>


 #include "android/log.h"
 static const char *TAG = "serial_port";
 #define LOGI(fmt, args...) __android_log_print(ANDROID_LOG_INFO,  TAG, fmt, ##args)
 #define LOGD(fmt, args...) __android_log_print(ANDROID_LOG_DEBUG, TAG, fmt, ##args)
 #define LOGE(fmt, args...) __android_log_print(ANDROID_LOG_ERROR, TAG, fmt, ##args)
 int fd;
 static speed_t getBaudrate(jint baudrate)
 {
switch(baudrate)
{
    case 0:
        return B0;
    case 50:
        return B50;
    case 75:
        return B75;
    case 110:
        return B110;
    case 134:
        return B134;
    case 150:
        return B150;
    case 200:
        return B200;
    case 300:
        return B300;
    case 600:
        return B600;
    case 1200:
        return B1200;
    case 1800:
        return B1800;
    case 2400:
        return B2400;
    case 4800:
        return B4800;
    case 9600:
        return B9600;
    case 19200:
        return B19200;
    case 38400:
        return B38400;
    case 57600:
        return B57600;
    case 115200:
        return B115200;
    case 230400:
        return B230400;
    case 460800:
        return B460800;
    case 500000:
        return B500000;
    case 576000:
        return B576000;
    case 921600:
        return B921600;
    case 1000000:
        return B1000000;
    case 1152000:
        return B1152000;
    case 1500000:
        return B1500000;
    case 2000000:
        return B2000000;
    case 2500000:
        return B2500000;
    case 3000000:
        return B3000000;
    case 3500000:
        return B3500000;
    case 4000000:
        return B4000000;
    default:
        return -1;
}
 }

 /**

 * 设置串口数据，校验位,速率，停止位

 * @param nBits 类型 int数据位 取值 位7或8

 * @param nEvent 类型 char 校验类型 取值N ,E, O,,S

 * @param mStop 类型 int 停止位 取值1 或者 2

 */

 int set_opt(jint nBits, jchar nEvent, jint nStop)
 {

LOGE("set_opt:nBits=%d,nEvent=%c,nSpeed=%d,nStop=%d", nBits, nEvent, nStop);
LOGE("set_opt:nStop=%d",  nStop);

struct termios newtio;

if(tcgetattr(fd, & newtio) != 0)
{

    LOGE("setup serial failure");

    return -1;

}

bzero( & newtio, sizeof(newtio));

//c_cflag标志可以定义CLOCAL和CREAD，这将确保该程序不被其他端口控制和信号干扰，同时串口驱动将读取进入的数据。CLOCAL和CREAD通常总是被是能的

newtio.c_cflag |= CLOCAL | CREAD;


switch(nBits) //设置数据位数
{

    case 7:
        LOGE("设置数据位数==7");
        newtio.c_cflag &= ~CSIZE;

        newtio.c_cflag |= CS7;

        break;

    case 8:
        LOGE("设置数据位数==8");
        newtio.c_cflag &= ~CSIZE;

        newtio.c_cflag |= CS8;

        break;

    default:
        newtio.c_cflag &= ~CSIZE;

        newtio.c_cflag |= CS8;
        LOGE("设置数据位数==默认=8");
        break;

}



switch(nEvent) //设置校验位
{
    case 'o':
    case 'O':

        newtio.c_cflag |= (PARODD | PARENB);
        newtio.c_iflag |= INPCK;
        LOGE("设置校验位O奇校验位");

        break;
    case 'e':
    case 'E':

        newtio.c_cflag |= PARENB;
        newtio.c_cflag &= ~PARODD;
        newtio.c_iflag |= INPCK;



        LOGE("设置校验位E偶校验位");

        break;

    case 'N':
    case 'n':
        newtio.c_cflag &= ~PARENB; //清除校验位


        LOGE("设置校验位N");
        break;


    default:
        newtio.c_cflag &= ~PARENB; //清除校验位
        LOGE("设置校验位默认N");
        break;

}
switch(nStop) //设置停止位
{

    case 1:

        newtio.c_cflag &= ~CSTOPB;

        break;

    case 2:

        newtio.c_cflag |= CSTOPB;

        break;

    default:
        newtio.c_cflag &= ~CSTOPB;
        // LOGW("nStop:%d,invalid param", nStop);

        break;

}

newtio.c_cc[VTIME] = 0;//设置等待时间

newtio.c_cc[VMIN] = 0;//设置最小接收字符

tcflush(fd, TCIFLUSH);

if(tcsetattr(fd, TCSANOW, & newtio) != 0)
{

    LOGE("options set error");

    return -1;

}


LOGE("options set success");
return 1;

 }


 /*
  * Class:     android_serialport_SerialPort
  * Method:    open
  * Signature: (Ljava/lang/String;II)Ljava/io/FileDescriptor;
  */
 JNIEXPORT jobject JNICALL Java_android_1serialport_1api_SerialPort_open
    (JNIEnv *env, jclass thiz, jstring path, jint baudrate,
     jint databits, jint stopbits, jchar parity)
 {

speed_t speed;
jobject mFileDescriptor;

/*波特率 */
{
    speed = getBaudrate(baudrate);
    if (speed == -1)
    {
        /* TODO: throw an exception */
        LOGE("Invalid baudrate");
        return NULL;
    }
}

/* Opening device */
{
    jint flags = 0;
    jboolean iscopy;
    const char *path_utf = (*env)->GetStringUTFChars(env, path, &iscopy);
    LOGD("Opening serial port %s with flags 0x%x", path_utf, O_RDWR | flags);
    fd = open(path_utf, O_RDWR | O_NONBLOCK);
    //fd=fd;
    LOGD("open() fd = %d", fd);
    (*env)->ReleaseStringUTFChars(env, path, path_utf);
    if (fd == -1)
    {
        /* Throw an exception */
        LOGE("Cannot open port");
        /* TODO: throw an exception */
        return NULL;
    }
}

/* Configure device */
{
    struct termios cfg;
    LOGD("Configuring serial port");
    if (tcgetattr(fd, &cfg))
    {
        LOGE("tcgetattr() failed");
        close(fd);
        /* TODO: throw an exception */
        return NULL;
    }

    cfmakeraw(&cfg);
    //设置波特率
    cfsetispeed(&cfg, speed);
    cfsetospeed(&cfg, speed);

    if (tcsetattr(fd, TCSANOW, &cfg))
    {
        LOGE("tcsetattr() failed");
        close(fd);
        /* TODO: throw an exception */
        return NULL;
    }

    //配置校验位 停止位等等
    set_opt(databits, parity, stopbits);
}

/* Create a corresponding file descriptor */
{
    jclass cFileDescriptor = (*env)->FindClass(env, "java/io/FileDescriptor");
    jmethodID iFileDescriptor = (*env)->GetMethodID(env, cFileDescriptor, "<init>", "()V");
    jfieldID descriptorID = (*env)->GetFieldID(env, cFileDescriptor, "descriptor", "I");
    mFileDescriptor = (*env)->NewObject(env, cFileDescriptor, iFileDescriptor);
    (*env)->SetIntField(env, mFileDescriptor, descriptorID, (jint)fd);
}

return mFileDescriptor;

 }

 /*
  * Class:     cedric_serial_SerialPort
  * Method:    close
  * Signature: ()V
  */
 JNIEXPORT void JNICALL Java_android_1serialport_1api_SerialPort_close
    (JNIEnv *env, jobject thiz)
 {
jclass SerialPortClass = (*env)->GetObjectClass(env, thiz);
jclass FileDescriptorClass = (*env)->FindClass(env, "java/io/FileDescriptor");

jfieldID mFdID = (*env)->GetFieldID(env, SerialPortClass, "mFd", "Ljava/io/FileDescriptor;");
jfieldID descriptorID = (*env)->GetFieldID(env, FileDescriptorClass, "descriptor", "I");

jobject mFd = (*env)->GetObjectField(env, thiz, mFdID);
jint descriptor = (*env)->GetIntField(env, mFd, descriptorID);

LOGD("close(fd = %d)", descriptor);
close(descriptor);
 }